1. Chapter 6 The Muscular System
Essentials of Human Anatomy & Physiology
Seventh Edition
Elaine N. Marieb
Chapter 6 The Muscular System
Slides 6.1 – 6.17
Lecture Slides in PowerPoint by Jerry L. Cook
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

2. The Muscular System Named for Latin word “mus” meaning little mouse
Dominant tissue in heart and the walls of other hollow organs
Essential function is to shorten or contract
Responsible for all body movement
Slide 6.1
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3. The Muscular System Three basic muscle types are found in the body
Skeletal muscle
Cardiac muscle
Smooth muscle
Differ in cell structure, location in body and how they’re stimulated to contract
Slide 6.1
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4. Characteristics of All Muscle Types
Muscle cells are elongated & called fibers
Contraction of muscles is due to the movement of myofilaments
All muscles share some terminology
Prefixes myo & mys refers to muscle
Prefix sarco refers to flesh
Slide 6.2
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5. Skeletal Muscle Characteristics
Most are attached by tendons to bones
Cells are cigar shaped & multinucleate
Striated – have visible banding
Largest of the muscles (up to 1 foot)
Voluntary – subject to conscious control
Often react involuntarily or by reflex
Slide 6.3
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6. Skeletal Muscle Characteristics
Can contract rapidly & with great force but tires easily
Fibers (cells) are surrounded and bundled by connective tissue
This allows skeletal muscle to exert great force without damaging the muscle fibers
Slide 6.3
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7. Connective Tissue Wrappings of Skeletal Muscle
Endomysium – around single muscle fiber
Perimysium – around a fascicle (bundle) of fibers
Figure 6.1
Slide 6.4a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

8. Connective Tissue Wrappings of Skeletal Muscle
3 layers of connective tissue: endomysium, perimysium & epimysium
Each layer gets thicker & tougher
Figure 6.1
Slide 6.4b
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9. Skeletal Muscle Attachments
Epimysium blends into a connective tissue attachment, usually a tendon which attaches to a bone
Sites of muscle attachment
Bones (attached by tendon)
Cartilages
Connective tissue coverings of muscles
Slide 6.5
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10. Smooth Muscle Characteristics
Has no striations
Spindle-shaped cells
Single nucleus
Involuntary – no conscious control
Found mainly in the walls of hollow organs
Figure 6.2a
Slide 6.6
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11. Smooth Muscle Characteristics
Arranged in sheets or layers – one runs circular or around & the other runs up and down
2 layers take turns contracting & relaxing to change shape of organ and move food or waste through the digestive system, etc
A slow steady contraction that goes on almost continuously
Figure 6.2a
Slide 6.6
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12. Cardiac Muscle Characteristics
Has striations
Usually has a single nucleus
Involuntary
Found only in the heart
Joined to another muscle cell at an intercalated disc
Figure 6.2b
Slide 6.7
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13. Cardiac Muscle Characteristics
Muscle is arranged in spirals or figure 8s
This causes the chambers to get smaller & squeeze the blood out when it contracts
Contracts at a steady rate controlled by the heart’s pacemaker – nervous system can speed it up
Figure 6.2b
Slide 6.7
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings